Quantum lights vs COB lighting??

The best board in efficiency of output is the qb288v2's based on the samsung 301b diode. I debate with myself though if you have a larger setup if the 288 is better then twice as many qb132's for even coverage.

The qb288's and 304's are very crowded with leds and that produces more of a traditional hot spot effect in the grow area where the middle of the tent's par numbers are 3 times higher then the outside edge.

Running twice as many boards that are 30% larger to begin with gets you much better spread of output and better cooling.

 

It's basically what I use. I have qb304 boards in mine but I have 2 qb260's in a 4x4. It's quite even coverage. I like to be able to run them at different heights and spacing.

 

I run cheap 45w ebay leds now and they are OK not much output so far - I have 2 boards over each of my 4 spots in bloom dont suggest them
4pcs 225 LED Grow Light Ultrathin Panel Indoor Garden Flower Veg Plant Lighting | eBay
I found the samsung 304 boards out there pretty cheap in all spectrums they can take more wattage - the drivers are not expensive on ebay - and home depot sells thin sheet aluminum pretty cheap for heat sink - all together I figured I can put together 4- 2board sets with drivers for around $300.00 - $400.00

 

have never used CMH, but...... swapped from HPS and MH to QB 135w's, 3000k and 4000k spectrums,
swapped to QB's a month ago and so far they are doing great.!!!
a 4000k 135w is vegging crazy good, covering a 5.5 sq ft area (25"x32") (25 wpsf)
another 4000k (turned down to ~90%) and a 3000k over another 5.5 sq ft for flower, (~47 wpsf)
they seem to be doing very good also, but i think 2 3000k's would have been even better, only time will tell.!!

 

maybe I can offer some experience. I started off building cobs right around the time hlg's "quantum boards" took off. at that time I used 4 pc fan powered heat sinks and 3/4"s aluminum angle with 4 vero 29 g7 cobs paired to a hlg320-c2100a. end cost was about 550 bucks. my view on the light is they are superior for penetration often suited for the parameter or if there are breaks in the canopy that have foliage below.

now I'm all about the quantum boards three 288's with 3/16" sheet aluminum, same driver for about 450 bucks these are really good for scrog or sea of green and they disperse the light far wide and even but I find that they don't have the penetrating power as the cobs do and are more suited for the inner canopy.

each is a good light just depends your style of growing.

 

My bud quality has never been better. I'm very excited to get mine tested. We have a testing facility opening up soon locally. Before now you had to physically escort your sample to be tested to a lab and there wasn't one for hundreds of miles on another island.

I'll tell you what I make frequent yearly trips to Wa, Oregon, and Cali. I've also had dispensary bud in Vegas. I've bought most times 25-30% THC. You know what I notice? My bud is better. Those 30% strains I've bought definitely don't put my bud to shame.

I don't have any lab tested numbers for you but just one stoners opinion. These qb lights grow high quality killer bud. It actually seems denser then HPS grown if you ask me. More smaller denser buds where HPS buds tend to be more fluffy.

 

I was just at a party on the weekend and a buddy of mine broke out his new favorite from our local dispensary. We tried it which was about 25% then we toked a bowl of mine. There was a clear winner and it wasn't the dispensary bud.

 

This is true from what I've seen and heard. Traditional 30mm size cobs with lenses penetrate better then qb's. You know why? There's no lenses on 99% of people's qb boards even though they do sell them. They work so good with no lenses at all that nobody bothers.

They not only have lenses they also have reflectors that fit on the outside of the heatsinks that nobody uses as well.

I often wonder that if you did a fair comparison where the qb fixture had lenses and reflectors like the cree, vero, or citizen cobs if they would be behind in penetration? Since the samsung leds themselves are about 20% or more efficient then any 30mm cobs I've seen I bet they do pretty well with lenses.

The only par tests I've seen with reflectors on the outside of the fixtures were done by LED gardner on youtube on a qb260. In on open space the reflectors raised the par numbers by 25%. In a tent it was only about 10% but I bet that was pretty significant for penetration.

 

I've had an idea for a while to mount a qb fixture inside of a 600-1000watt hps vented rectangular hood. It would not only help with reflecting more light downward but it would also cool wonderfully with the heat duct on top and an exhaust fan.

 

I was to cheap to buy lenses or those other refractory do dads for my setup. Plus I wanted to have the lights lower due to tent setup and at the time I was aiming for a cob/as ft

I totally get your point.

Also another key point I forgot to mention is radiant heat is different between the two styles as well. With cob being the further reaching

 

I found the 304 boards in 2700K and 3000K that is what I am going to use in bloom and 4700k and 5000k for veg- that is my plan once funds free up - for now my cheaps do OK but not much output so far only 2 weeks in with this run - 1st run I over fed and burned up so we shal see

 

I got by with burple lights for two years before I got some qb lights. With the price difference I would recommend the qb288v2's over the 304's. The 304's are the hottest running board they sell. If you have any temp difficulties it's not the best choice. The qb288v2 is much cooler running then even the old 288 because of the more efficient diode and Samsung's superior manufacturing techniques compared to the contractors that built all previous HLG boards. Samsung puts a special reflective coating on the board itself that helps reflect more light downward along with the more efficient diode. All those things work to make the V2 a much cooler running board even at full output then the 304.

 

yes - but the wattage of the 304s is higher and I am only gong to use a minimal count on the boards + I use vented aluminum for heat sink and it cools real well -we did this setup for a friend of mine recently and it works well the plants can actually touch the boards for a short time without getting burnt

 

They do take some learning because they typically change your nutrient routine when you change lighting systems. The qb's increase nutrient uptake compared to the burples I was using. They need more calcium. They plants like higher temps under qb's for more rapid growth I target 80-82.

 

Yeah - it will be a fun experience the cheap burples I have do pretty good - they are Red, Blue, White, Orange and UV

 

304's are no joke and they do sell at a discount right now because they are the older LM561c s6 diodes. They used to have the highest efficiency because of their particular layout. They are about 2.6umol/watt at full power. Just behind the new v2 boards really by 5% or so in efficiency of output.

It's because the 304's work off of double the voltage compared to the qb288. The 304's like about 110 volts per board DC. That's why they were never used in the HLG 4 board fixtures. If you want to use 4 boards and one driver the voltage requirements of the boards are too high for series wiring.

At double the voltage the qb304 runs off of half the current. I use 1050mA drivers on mine so half the current of the 2100mA that is common with the 288 in the qb260 but twice the voltage.

Higher voltage means less current loss over the course of a circuit or load. That's why the electric company brings electricity to your house at thousands of volts and then it is stepped down to working home voltages by the closest transformer to your home on the pole and on to the lower voltage section of the power pole.

When power companies need to transmit electricity over long distances they step up the voltage to minimize the loss. That's why the 110volt 304 board was the beast before the V2 came along.

Personally I buy a light setup to last for year or more and a crop is worth thousands so I don't sweat spending an extra $20 per board on the more efficient cooler running boards but it's your choice. They weren't available when i built my setup.